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The Federal Communications Commission (FCC) said today that it will not approve LightSquared's proposal to build a national 4G-LTE network, after testing showed that the network would interfere with most existing GPS devices.

The decision came swiftly after the National Telecommunications and Information Administration (NTIA) today warned the FCC that "LightSquared's proposed mobile broadband network will impact GPS services and that there is no practical way to mitigate the potential interference at this time." The FCC responded by indefinitely suspending LightSquared's conditional waiver to operate the network, the Washington Postand others are reporting. The FCC will also issue a public notice on Wednesday seeking comment on the NTIA's conclusions. The conditional waiver had been issued in January 2011.

LightSquared proposed to build an open-access, wholesale wireless broadband network integrating satellite and terrestrial technology, but government testing showed that the network would harm performance of 75 percent of GPS devices. GPS makers and the airline industry (which is building a GPS-based navigation system) were among numerous groups objecting to the plan, raising pressure on the FCC to block it. LightSquared can still fight on, but the NTIA recommendation and subsequent FCC decision dramatically reduce its chances of final success.

LightSquared controls spectrum originally intended for satellite communication, and wants approval to use it for terrestrial broadband service. The spectrum is adjacent to that used by GPS, and GPS makers complain the LightSquared signals will be so powerful they would cause widespread jamming of GPS devices. LightSquared has long insisted that the problem lies with the GPS community, which should have to redesign its receivers.

LightSquared has renewed its bitter complaints that the GPS industry has become "too big to fail" and is being protected by government even though its receivers often don't filter frequencies properly and "listen" on adjacent spectrum, including that now held by LightSquared.

"You can get a cell phone for free with a two-year contract that is more resilient to GPS interference than what’s being installed in today’s commercial airliners," the company said, though it pledged to keep working on a solution.

"This proceeding has revealed challenges to maximizing the opportunities of mobile broadband for our economy," the FCC said in a statement. "In particular, it has revealed challenges to removing regulatory barriers on spectrum that restrict use of that spectrum for mobile broadband. This includes receivers that pick up signals from spectrum uses in neighboring bands. There are very substantial costs to our economy and to consumers of preventing the use of this and other spectrum for mobile broadband. Congress, the FCC, other federal agencies, and private sector stakeholders must work together in a concerted effort to reduce regulatory barriers and free up spectrum for mobile broadband. Part of this effort should address receiver performance to help ensure the most efficient use of all spectrum to drive our economy and best serve American consumers."

There is still a good amount of unused spectrum that LTE will be rolled out in over the next two years. Verizon has 20MHz of almost nationwide coming in those cable company AWS spectrum purchases, along with the other 20MHz AWS spectrum they own in the eastern half of the US means they could increase their LTE coverage by 150%. CLEAR also has a lot of spectrum - 75-196MHz around major metro areas in the US. Their main problem is that its at 2.6GHz and there are signal strength issues indoors. But 50MHz of TD-LTE-Advanced would offer users tremendous speeds, around 25Mb/s.

All carriers out there (except for Verizon) are short on spectrum. But thats no reason to trash GPS or anything else we have so you can reach your 2GB monthly data transfer cap quicker.

As great a product they were hoping to deliver, risking the security of GPS doomed it from the get go.

Hopefully the satellite can be re- purposed somehow, and the rest of the investment recovered with as little loss as possible.

The problem isn't with using the satellite! That was the point of that frequency allocation, a space-based chunk of spectrum, adjacent to other space-based services. So Lightsquared can continue to use the spectrum they have for the purposes for which it was originally licensed: a space-based communications system. Too bad they doesn't seem to be as much of a market for that type of service as compared to a terrestrial service that LIghtsquared wanted to build, but DIDN'T HAVE SPECTRUM FOR.

It was the waiver they sought to bring the transmitters out of geosynchronous orbit, and put it on the ground that was the whole problem here.

Even political influence will occasional bump up against the laws of physics, which mostly cannot be denied.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

That is what I read.

Honestly, I feel like LightSquared is getting screwed over. Spectrum so close to GPS's shouldn't have been licensed out in the first place. Now LightSquared has paid for something they can't even use.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal.

They pick it up because the signal is much more powerful than should ever be encountered in the mobile satellite spectrum.

Quote:

If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

But they paid for spectrum where the FCC in the past has explicitly said it was not meant for a stand-alone terrestrial network and where there are Federal regulations that specifically forbid interference from terrestrial transmitters to other users..

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

You only have part of the story here. LS purchased the spectrum from a third party. This spectrum was always intended for satellite comms. LS intended to use said spectrum for terrestrial comms at power levels about a billion times stronger than satellite signals. FCC said that they could only do this if they could prove it didn't interfere with GPS. They could not. This is entirely on LS's shoulders, not on GPS makers.

At power levels WAY beyond what the spectrum is licensed for. There was no way for most GPS receivers to get their satellite signal against that kind of interference; it was drowned out by the strength of the satellite-repurposed-for-terrestrial approach of LS. Think of trying to see a candle halfway across town, when the candle is next to a high-powered spotlight shining at you. You can make each one a different color but that doesn't help because the spotlight is just too bright. Satellite signals are necessarily weak because of the distances involved, and the limited power supplied by orbiting satellites. GPS units need to be sensitive to very weak signals. LightSquared bought spectrum that was supposed to be used for these weak transmissions and decided to pump up the power a few billion times so that they'd carry over ground and penetrate through buildings. Interference with adjacent frequencies is pretty much unavoidable if you do that. Filtering out the billion-times-stronger signal is difficult and infeasible, and would be prohibitively expensive. The thing is that LightSquared should have known this going in (I find it hard to believe that they didn't), and by the time of the testing they had no excuse to deny the physics. They are not the victims here unless whoever came up with their business plan decided to lie about physics. Even then, by the time things got to the testing phase they should have been able to see the problem. It wasn't the GPS industry's shortcuts, it was theirs. They tried to get around the existing licensing requirements for that slice of spectrum, rules guided by basic physical laws. They have nobody to blame but themselves, and now they're trying to poison the well by bullshitting about over-regulation and slandering the GPS industry. Nothing they say is based on sound physics, engineering, or smart licensing policies. What they wanted was a special privilege to stomp all over neighboring spectrum with impunity; the fact that neighboring spectrum happens to be occupied by one of the most important technologies around made no difference.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

Only slightly true.

The problem is that the signal from the GPS satellites are so faint, any nearby (both in terms of physical distance and frequency ranges) ground emission of RF will destroy the signal.

GPS devices, especially high-precision devices, are tuned to listen to the full GPS band. It is able to ignore everything that isn't part of the GPS band by using whats called a band-pass filter (hey that electrical engineering stuff I learned in college is coming in handy!). However the band-pass filter is not perfect, and the edges of that filter "roll off", which means the edges are round, not square. So you allow the GPS band to pass, but end up including some adjacent parts of the neighboring frequency bands.

This was fine when the neighboring spectrum was also used by satellite, but when you add in the ground towers at something like 100,000x the effective power, it destroys the GPS signal and you cant lock on the signal. Similar to someone screaming in your ear while you try and hold a conversation with someone across the table from you.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

Please go read the comments to the other articles to get the whole story; unfortunately, the Ars writers never seem to give the correct background. Nano-summary: LightSquared bought satellite-to-surface spectrum right next to GPS frequencies and tried to get the FCC to allow them to repurpose the spectrum for surface-to-surface. This means that the sideband power that the GPS receivers would have to reject is about one billion times greater than they were designed to; that sort of thing is why the FCC didn't have surface-to-surface spectrum chockablock with satellite-to-surface spectrum in the first place...

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

go and read some of the other articles and comments on ars.

Lightsquared wanted to use the space based spectrum to broadcast from earth based towers at a power level millions of times higher than the expected power levels in that spectrum.

This is a victory for common sense and deserved comeuppance for the hedge fund scum who owns LS. They purchased a spectrum license for satellite transmission in frequencies adjacent to the GPS bands. If they actually used it in the way it is licensed it would work fine but they want to instead do terrestrial transmission that is a billion times more powerful where the signals are received. That will mess up many GPS receivers and is not allowed in the license.

Consequently the FCC has correctly denied them access and told them to shove it. Sweet justice! The bait and switch LS tried to pull with their (mis)use of the license didn't work. And the hedge fund parasite has 60% of his fund invested in the now worthless LS, so he's taking a huge, deserved hit for his arrogance in thinking basic rules don't apply to him. Enjoy the sweet sound of your ill-gotten dollar bills burning, jerk! And get off the stage so someone with brains and integrity can put the spectrum to good use without screwing up GPS.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

That is what I read.

Honestly, I feel like LightSquared is getting screwed over. Spectrum so close to GPS's shouldn't have been licensed out in the first place. Now LightSquared has paid for something they can't even use.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

Please go read the comments to the other articles to get the whole story; unfortunately, the Ars writers never seem to give the correct background. Nano-summary: LightSquared bought satellite-to-surface spectrum right next to GPS frequencies and tried to get the FCC to allow them to repurpose the spectrum for surface-to-surface. This means that the sideband power that the GPS receivers would have to reject is about one billion times greater than they were designed to; that sort of thing is why the FCC didn't have surface-to-surface spectrum chockablock with satellite-to-surface spectrum in the first place...

This. I leave both quotes in because GaryThedons' was my original opinion, too, thinking that LightSquared was getting screwed, until I read the comments from all of you folks on the previous articles and my understanding of the true story became complete.

While I do feel for the loss of what LightSquared was proposing to do, they didn't do their homework anywhere nearly as thoroughly as they should have (and would have avoided all this if they had). In this case, the government, GPS and aviation industries are all in the right, with LightSquared clearly in the wrong.

I was bracing myself for a flood of comments by people who didn't know the background to this and therefore were of the opinion that LightSquared was in the right - fortunately a bunch of commenters have beaten me to it.

Anything said by LS should be taken with a hefty grain of salt if not outright ignored, the company has been spouting what ammounts to raw bullshit over this issue ever since it arose.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

Only slightly true.

The problem is that the signal from the GPS satellites are so faint, any nearby (both in terms of physical distance and frequency ranges) ground emission of RF will destroy the signal.

GPS devices, especially high-precision devices, are tuned to listen to the full GPS band. It is able to ignore everything that isn't part of the GPS band by using whats called a band-pass filter (hey that electrical engineering stuff I learned in college is coming in handy!). However the band-pass filter is not perfect, and the edges of that filter "roll off", which means the edges are round, not square. So you allow the GPS band to pass, but end up including some adjacent parts of the neighboring frequency bands.

This was fine when the neighboring spectrum was also used by satellite, but when you add in the ground towers at something like 100,000x the effective power, it destroys the GPS signal and you cant lock on the signal. Similar to someone screaming in your ear while you try and hold a conversation with someone across the table from you.

Yes, but the bandpass rolloff could be fixed by requiring (a) a certain bandpass fidelity and (b) a narrow gap in the rolloff region. That said, GPS devices should have had bandpass filters from the getgo. I love me GPS, but it's still damn lazy and shortcutted design. Not designing for it is assuming in perpetuity that the adjacent signal space will remain weak enough to not interfere, which, well, is just stupid.

Lightsquared's claim that GPS devices were broadcasting into the LS spectrum was an attempt to change the past to justify their current actions.'Long ago, in the time of the moon landings, all broadcasting was analog.The license was a slice of spectrum that held a signal that was fuzzy around the edges and was likely to spread beyond the band.Bands had to be separated by white space to prevent interference.

That is the time when weak fuzzy signals were perfectly OK.Little did we expect that the unused spectrum between bands would become 'wasted spectrum' , an unused resource that had to be reallocated to use the spectrum efficiently. Remember the TV changed to digital and old sets stopped working?

Lightsquared said that it was the FCCs job to forsee new technology so that, when analog bands were replaced by digital, LS claimed that there new digital band had more rights than the existing users.

LS was so confident that new bands ruled, they did not buy the Dish network's band when it was available- that did not cause interference with GPS - so instead of making money on broadband, they have nothing.,This is like building a new house on somebody else's land and wondering what the fuss is about. It's flatly ridiculous.Had they had competent scientific advice, LS would own the Dish bands and be in the process of rolling out a new network. However, all their strategy was based on changing regulations and avoiding facts.

LS failure should be a reminder that facts are stubborn things that cannot be wished away.

Another point is that GPS signals are resilient to interference: unless some other signal completely swamps it, like "drives the RF amps to saturation" type swamping, the GPS hardware could still pull the signal out. After all, from the standpoint of a GPS receiver listening to one satellite, even the signals from all the other GPS satellites are noise. It's the same sort of tech that allows them to put two antennas on your wireless-N wi-fi router, both transmitting on the same channel, and almost double the speed - the network adapter is able to differentiate the two signals. It's as near to magic as I can think of.So, if lightsquared used their spectrum in accord with their license, then GPS receivers could have dealt with their signal, at full strength, without interference. Device manufacturers took advantage of this, including the whole satellite-only band in their bandpass filters, to make their equipment flexible. If someone put up a new constellation of GPS satellites using another part of the band, existing GPS receivers would be a firmware upgrade away from using them. Perhaps, maybe, even the GPS hardware in my phone could be re-purposed to pick up and use a new satellite data service! (Lightsquared would certainly be planning to use GPS receiver chips and designs in their equipment.)But they don't want to use their licensed spectrum in accord with their license, and that is too bad for them. Go buy some terrestrial spectrum and stop fudding up our news.

From my understanding they were broadcasting within their spectrum, but that GPS receivers are designed to pick u such faint signals they the were picking up the nearby LS signal. If thats true, I can't help but feel for LightSquared, they paid for something and are now being told they can't use it because of someone elses shortcuts.

Please go read the comments to the other articles to get the whole story; unfortunately, the Ars writers never seem to give the correct background. Nano-summary: LightSquared bought satellite-to-surface spectrum right next to GPS frequencies and tried to get the FCC to allow them to repurpose the spectrum for surface-to-surface. This means that the sideband power that the GPS receivers would have to reject is about one billion times greater than they were designed to; that sort of thing is why the FCC didn't have surface-to-surface spectrum chockablock with satellite-to-surface spectrum in the first place...

That is probably the best way to put it. Happy and Sad. Happy for the continued assurance of GPS, sad that a seemingly good idea turned out to fail so miserably...

Dish is trying essentially the same thing at 2 GHz.

Yes this is important! There's no GPS interference at their frequencies. This would open up new bands for LTE.

Dish isn't going to use the frequencies it uses for satellite television (they aren't going to interfere with themselves). Dish is buying the frequency bands from bankrupt satellite companies DBSD and Terrestar. Google searching shows that Canada has approved the transfer, but the FCC hasn't yet:

In any case, Dish says it will take them 3 years to develop the LTE infrastructure (unless they partner with some other company---they've talked about working with Sprint or T-Mobile, or maybe they'll get over their fight with AT&T).

Yes, but the bandpass rolloff could be fixed by requiring (a) a certain bandpass fidelity and (b) a narrow gap in the rolloff region. That said, GPS devices should have had bandpass filters from the getgo. I love me GPS, but it's still damn lazy and shortcutted design. Not designing for it is assuming in perpetuity that the adjacent signal space will remain weak enough to not interfere, which, well, is just stupid.

They do have filters and no its not stupid when everyone in the world agreed to use this range for sat only. And how do high precision units receive the correction data from Imarsat then considering that it's frequency is inside the Lightsquared spectrum? Not a problem if they are both at sat power levels but Lightsquared wouldn't be. Planes/farming/construction would all be impacted by this. What about The Russian and European GPS systems, since narrow band filters would block them too? So back to US-only and international phones then... Sat-Com is an international problem we cannot have one national agency piss all over sat spectrum just because someone took a bung.

In any case Lightsquared were quite explicit they still intended to use the top half of their frequency (the current plan was just a stopgap to get their toe in the door). No real world filter CAN be designed with sufficient roll-off to reject the top half of their frequency range, and inter-modulation between their low and high bands would have caused unavoidable spillover into the L1 GPS band anyway. Why invest all this money to fix a problem when your fixes are going to break in a few years anyway?

"tried to get the FCC to allow them to repurpose the spectrum for surface-to-surface. This m"

The satellite communications is a 'good thing. Perhaps if the spectrum can be traded (or bought) to 'translate'on another signal band. They could still be in business. Dont know what band that would be but when they've got the bandwidth from the top down,and need something to 'translate' across.

If it is actually the sideband that is the problem. Or trade the gps bandwidth for a different satellite bandwidth. With a gps company that has a couple sets. Perhaps.

Fact is it's time to mandate all future GPS devices have the filtering technology to avoid this type of interference so in 10 years time we can revisit the issue without the problem of GPS using sections of spectrum they were never meant to and were meant to stop using over 10 years ago. It's not possible for LightSquared to go ahead now but it is possible for us to start addressing the interference issue by mandating proper use for all future GPS devices so that in the future this will be a non-issue and we can expand our use of spectrum even further than what is possible today.

"You can get a cell phone for free with a two-year contract that is more resilient to GPS interference than what’s being installed in today’s commercial airliners,"

Stuff like this is what hardened me against the company as a ethical entity. This is a gross misrepresentation of the situation. Phones use a variety of technologies not related to sattalite GPS to improve thier performance(aGPS, predictive software, IP/server connectivity logs, etc) plus do not have to be precise to less than 30' or so. A cell phone can handle a significant amount of interference because it is not a high precision device and has a ton of fallback/augmented methods of finding location. Normal GPS devices have none of this and generally are far more precise.

Its an Apples to Oranges comparison, and LS knows it. Its an argument that sounds good to people who know nothing on the topic. But they know that and continue to construct and beat down that straw man.

Given this lack of ethics, why does anyone trust that their business model would be nearly as altruistic as they are presenting it? They've shown a willingness to bend the truth and distort facts to get their way. Do we really need another sociopathic company controlling communications?